......but you only get #N/A if C5 doesn't find a match in the first column of data, if it matches but finds a blank in the return column that isn't an error so you won't eliminate it by using ISNA

If the first VLOOKUP returns a blank and the second one doesn't (or vice versa) what do you want to do then?

Is it possible that C5 won't be in the first column of data?